Protein peptide hydrogels

Abstract

The present invention broadly provides novel peptides that can be used to form hydrogels. The peptides are short (preferably 30 amino acid residues or less) and include hydrophilic and hydrophobic segments joined by a turning segment. The hydrogels are formed by altering the pH of a solution of these peptides to an acidic level, or by introducing a source of ions into a solution of these peptides. The resulting hydrogels are shear thinning gels that have high storage moduli and high rates of recovery after destruction. They find use in medical applications, including tissue engineering.

We claim: 
     
       1. A gel comprising an amphiphilic peptide comprising a hydrophobic terminal region, a turning region, and a hydrophilic terminal region, said turning region being between said hydrophobic and hydrophilic terminal regions, wherein: said hydrophobic region comprises, in any order, amino acid residues of FLIVI (SEQ ID NO:4);
 said hydrophilic region is selected from the group consisting of: 
 [GPGXD] n  (SEQ ID NO: 15), where n is from 1 to 10, and each X is G or A; 
 GPGX 1 DGX 2 X 1 X 1 D (SEQ ID NO: 14), where each X 1  is individually selected from the group consisting of A, G, V, I, and L, and X 2  is selected from the group consisting of P, A, G, V, I, and L; and 
 GPGXD (SEQ ID NO: 16), where X is selected from the group consisting of A, G, V, I, and L; and 
 said turning region is selected from the group consisting of: 
 G, GG, GGG, GGGG (SEQ ID NO: 17), GSXX (SEQ ID NO: 18), XGSX (SEQ ID NO:19), XXGS (SEQ ID NO:20), SGXX (SEQ ID NO:21), XSGX (SEQ ID NO:22), XXSG (SEQ ID NO:23), GXSX (SEQ ID NO:24), XGXS (SEQ ID NO:25), SXGX (SEQ ID NO:26), XSXG (SEQ ID NO:27), GXXS (SEQ ID NO:28), SXXG (SEQ ID NO:29), where each X is individually selected from the group consisting of G, I, V, A, and L, and each S could be replaced by T. 
 
     
     
       2. The gel of  claim 1 , wherein said turning region consists of amino acid residues GSII (SEQ ID NO:30). 
     
     
       3. The gel of  claim 1 , wherein said hydrophilic region comprises amino acid residues of GPGGDGPGGD (SEQ ID NO:2). 
     
     
       4. The gel of  claim 1 , wherein said peptide comprises less than about 30 amino acid residues. 
     
     
       5. The gel of  claim 1 , wherein said peptide comprises the amino acid sequence FLIVIGSIIGPGGDGPGGD (SEQ ID NO:1). 
     
     
       6. The gel of  claim 1 , wherein said gel comprises said peptide dispersed, dissolved, or suspended in water. 
     
     
       7. The gel of  claim 1 , wherein said peptide is present in said gel at a level of from about 0.1% by weight to about 3% by weight, based upon the total weight of the gel taken as 100% by weight. 
     
     
       8. An amphiphilic peptide comprising a turning region, a terminal hydrophobic region and a terminal hydrophilic region, wherein:
 said hydrophobic region comprises, in any order, amino acid residues of FLIVI (SEQ ID NO:4); 
 said hydrophilic region is selected from the group consisting of: 
 [GPGXD] n  (SEQ ID NO: 15), where n is from 1 to 10, and each X is G or A; 
 GPGX 1 DGX 2 X 1 X 1 D (SEQ ID NO: 14), where each X 1  is individually selected from the group consisting of A, G, V, I, and L, and X 2  is selected from the group consisting of P, A, G, V, I, and L; and 
 GPGXD (SEQ ID NO: 16), where X is selected from the group consisting of A, G, V, I, and L; and 
 said turning region is selected from the group consisting of: 
 G, GG, GGG, GGGG (SEQ ID NO: 17), GSXX (SEQ ID NO: 18), XGSX (SEQ ID NO:19), XXGS (SEQ ID NO:20), SGXX (SEQ ID NO:21), XSGX (SEQ ID NO:22), XXSG (SEQ ID NO:23), GXSX (SEQ ID NO:24), XGXS (SEQ ID NO:25), SXGX (SEQ ID NO:26), XSXG (SEQ ID NO:27), GXXS (SEQ ID NO:28), SXXG (SEQ ID NO:29), where each X is individually selected from the group consisting of G, I, V, A, and L, and each S could be replaced by T. 
 
     
     
       9. The peptide of  claim 8 , wherein said peptide comprises less than about 30 amino acid residues. 
     
     
       10. The peptide of  claim 8 , wherein said peptide comprises the amino acid sequence FLIVIGSIIGPGGDGPGGD (SEQ ID NO:1).